Generally, ‘jeotgal’, a salted sea food containing fish sauces, is part of the traditional Korean fermented foods which have been used as materials for preparing Korean foods. In Korea, most marine products are utilized as fermented sea foods, being salted and fermented to be used as seasonings or subsidiary raw materials for making kimchi. Marine fermented sea foods usually refer to those prepared by adding a large amount of salt followed by fermentation and maturation through decomposition of protein raw materials by the activity of the protease contained therein, and the fish sauce refers to a juice separated from the fish sauce after fermenting for a longer period.
Jeotgals and fish sauces manufactured using marine products can provide a deep and savory taste due to maturation by enzymatic activity along with the unique flavor of the fish itself, and are usually used as seasonings for appetizers. In fact, they are used as subsidiary raw materials for making a seaweed soup, seasoned zucchini, and kimchi. In Korea, various kinds of jeotgals are manufactured depending on the part of the country, and also various kinds of kimchi prepared using the same are available. Recently, with the globalization of food materials, fish sauces are being imported as food materials from overseas, including from Southeast Asian countries.
Conventional fish sauces contain water, salt, and a small amount of amino acids, nitrogen, and calcium. An anchovy fish sauce (a representative fish sauce) contains a large amount of various amino acids, including glutamic acid, aspartic acid, glycine, alanine, lysine, etc., and taste compounds, such as nucleic acids, and thus it has been widely used in seasoning foods such as kimchies (whole cabbage kimchi, young radish kimchi, leaf mustard kimchi, etc.) and grilled foods.
Traditionally, these fish sauces were mainly manufactured at home and consumed in a self-sufficient manner, but nowadays they are being produced in large-scale factories with improved hygiene and storage capacity, and there is a growing demand for the fish sauces.
According to a traditional method for manufacturing the fish sauce, the material of a whole fish is mixed with salt and then put into a tank or container, allowed to ferment for a certain period (at least 24 months), and the resulting juice produced by lysis of the fish proteins is filtered to thereby obtain the fish sauce. Fish sauce manufactured using fish as a raw material, being a natural animal seasoning, has been used as an seasoning essential for manufacturing kimchi, and also in cooking a few other foods in Korea and is thus becoming one of the seasonings essential in Korean food culture.
When the fermentation is performed by the traditional method it requires a longer period for fermentation/maturation, during which the anchovy proteins are lysed by the autolytic enzyme contained in the fish, and also decomposed by various microorganisms which can grow in high salt conditions. Generally, fermentation can vary according to the kind and state of the microorganisms involved therein, and the contamination of various bacteria often accompany a foul odor and unpleasant taste.
Recently, there has been an increase in the production of a pacific sand lance sauce, but the pacific sand lance sauce, due to its foul odor and taste, can be used only in foods having a strong smell such as kimchi.
Additionally, because the traditional method requires a long period it cannot secure good productivity and competitiveness thus not being able to accelerate its progress in the related industry. Accordingly, various attempts have been made to shorten the fermentation period of the conventional fish sauces. For example, Korean Patent No. 10-0467500 (Quick fermented liquid Jeotgal using anchovies or lances and process of preparation thereof) suggests a method for manufacturing a fish sauce including adjusting pH, performing a tertiary maturation by adding an enzyme preparation, and sterilization/filtration. Additionally, Korean Patent No. 10-0034142 (method for making salted and soused liquid products from small sardine) discloses a method for manufacturing a fish sauce including adding a calcium salt as an enzyme activity accelerator and a protease to a ground meat, agitating at optimum pH and temperature conditions for 4 hours, and hydrolyzing, sterilizing, cooling, filtering, and adding salt to the filtrate.